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(CNN) -- New Jersey Gov. Chris Christie on Thursday apologized for the conduct of certain aides in orchestrating traffic jams near the George Washington Bridge to punish a political rival.

Christie said he was "embarrassed and humiliated" by the conduct of "some people on my team" and fired a senior aide at the center of the scandal that political commentators suggest could mean bigger problems for the potential Republican presidential candidate in 2016.

Christie gave anyone with knowledge of the incident affecting the town of Fort Lee over several days last September to come forward with information.

"I am responsible for what happens under my watch -- the good and the bad," he said at a news conference.

The governor said he had no knowledge or involvement of this issue in its planning and its execution.

"This was handled in a callous and indifferent way," Christie said.

Earlier, a state senator called for a federal investigation into Christie's administration over the allegations that rocked Trenton on Wednesday with the release of explosive e-mails involving political appointees in the state.

September lane closures near the world's busiest bridge connecting New Jersey to Manhattan snarled traffic for days in Fort Lee -- an event that was not only inconvenient but also potentially delayed emergency services, endangering people's lives, New Jersey state Sen. Ray Lesniak told CNN's "New Day."

"This crosses a line that is rarely crossed: People's lives were in danger," said Lesniak, a Democrat. "Endangering people's lives -- that's not politics. That's why the U.S. attorneys have to get involved."

Christie said he was "blindsided" by the release of the e-mails that suggested Christie appointees sought to punish Fort Lee Mayor Mark Sokolich, a Democrat who wouldn't support the governor at the polls in November.

Christie and his staff originally blamed the closures and the traffic delays on a mishandled traffic study.

Fort Lee officials said that an elderly woman who suffered a heart attack died after paramedics were delayed in reaching her because of traffic problems. Details of the woman's death haven't been released, but Lesniak suggested Thursday that the issue should be part of the investigation.

"There have been serious consequences as a result of these actions. Reckless endangerment of people's lives ... and someone died," he said.

Lesniak called for an investigation hours earlier on his Twitter account.

"Wow! Time for a federal grand jury. This smells of corrupt use of government authority at the highest levels," he tweeted.

While Lesniak is calling for a federal investigation, U.S. Sen. Jay Rockefeller, chairman of the Senate Commerce Committee, which oversees the Port Authority, indicated his desire for an investigation in December. He asked Transportation Secretary Anthony Foxx to review this incident.

"Unwarranted lane closures with no public notice can have serious ramifications on interstate commerce and safety in the region," the West Virginia Democrat said in a prepared statement last month. "I continue to have serious concerns about the actions of this agency."

'Time for some traffic problems'

The correspondence, subpoenaed by Democrats investigating the matter and spiced with tough Jersey political talk and expletives, is the most damaging evidence so far supporting their assertions that the move was orchestrated because Sokolich didn't endorse Christie's re-election.

The mayor said the traffic mess created serious hardships for commuters and other residents, and affected public safety in his community.

The exchanges began three weeks before access lanes to the bridge were closed, causing heavy traffic backups between September 9 and 13, two months before Election Day.

"Time for some traffic problems in Fort Lee," Bridget Anne Kelly, Christie's deputy chief of staff for legislative and intergovernmental affairs, said in an e-mail to David Wildstein, then the highest-level appointee representing the state at the Port Authority of New York and New Jersey, which operates the bridge connecting the two states.

"Got it," Wildstein replied.

In another message about school buses with students on board caught in the traffic jams, Wildstein writes, "they are the children of Buono voters," apparently referring to Barbara Buono, Christie's Democratic opponent in last November's gubernatorial election.

Those cited in the series of e-mails and text messages did not respond to requests for comment or to verify the communications.

Wildstein, who has left his job, is expected to appear at a legislative hearing Thursday.

Democratic New Jersey Assembly Deputy Speaker John Wisniewski said the e-mails call into question the integrity of the governor's office.

Christie,

he said, "has a lot of explaining to do."

"I do not believe the governor called the Port Authority and said, 'Close some lanes.' But I did say I hold him responsible for the atmosphere. Now finding that that atmosphere existed in his own office is what I find really troubling," Wisniewski said.

Christie's name did not appear in the e-mails, he added.

Emergency services disrupted

Sokolich told CNN's "The Situation Room" the e-mails suggested that political motives behind the lane closures have led him to believe that Christie is more clued-in than he's admitted.

"I'm rooting that the highest elected official in the state of New Jersey isn't involved. But I'm beginning to question my judgment," Sokolich said.

The mayor raised the issue of public safety being compromised. A letter by his emergency services coordinator, Paul Favia, on September 10 obtained by CNN cited a "new traffic pattern" around the bridge's toll plaza that was backing up traffic in Fort Lee.

"This new traffic pattern is causing unnecessary delays for emergency services to arrive on scene for medical emergencies," Favia said, citing one case in which paramedics rushing to aid an unconscious elderly woman suffering a heart attack were held up and had to meet the ambulance transporting the victim at the hospital instead of at the scene. She later died.

The situation could deepen Christie's political woes, said David Gergen, a CNN senior political analyst.

"If a woman died here," he said, "he's in deep, deep trouble."

Analysts: Bridge firestorm could have bigger impact on Christie

Even if he had nothing to do with the traffic snarls, the allegations could have serious consequences for Christie, analysts said.

"There's something about this that's so petty and so vindictive, and it feeds into this narrative that he's a bully. ... He's going to have to find some way to defuse this to prove he doesn't run a shop like that," said Gergen, a former adviser to several U.S. presidents.

It's a defining moment for Christie, said John King, CNN's chief national correspondent. And how he deals with the situation in the next two days -- from whether he fires anyone to what he says -- will be key.

"If he handles it decisively and then he sits down and calmly answers questions and doesn't berate the reporters who ask them, then he has a chance to be a leader who dealt with a crisis and he moves on," King said. "But if that perception starts to stick in, that's not a presidential temperament. And that's bad for him nationally in his perspective. It's bad for him as he starts his new term in New Jersey. And it's bad for him with the audience he needs to care about most politically long-term at the moment, and that's the Republican base that he wants to make him their nominee."

Does this mean Christie's presidential ambitions are dashed?

"Not necessarily," Oxford University historian Timothy Stanley wrote in an opinion piece for CNN.com. "He's a resourceful politician and it's still many months before campaigning starts in earnest. But now, his opponents have a stick to beat him with. Best of all, it's an anti-government stick. If Republicans stand for anything right now, it's opposing the ability of government to mess with the individual's life -- and here we have a classic example of politicians taking revenge on each other at the expense of the average citizen."

Political commentators from both sides of the aisle immediately recognized the potential for credibility questions, particularly around Christie's explanations in recent months about the traffic jams in Fort Lee and previous comments rejecting suggestions of political mischief.

"He's already cemented a narrative as something of a bully," said S.E. Cupp, a Republican political strategist and CNN "Crossfire" host. "If this was happening in his administration, I don't think it would be shocking."

But, she said, if it "turns out he's lying about what he knew or whether he ordered it -- that's going to be the worst, the most damaging; because his authenticity is his calling card."

It's important to ask how much Christie knew, Gergen said, but the reality might be more complicated.

"Sometimes the boss does not order something," Gergen said, describing the Nixon White House during the Watergate scandal. "I don't know whether Nixon ordered Watergate, but I can guarantee you that people who carried out Watergate thought that's what he would have wanted. There's an environment in which you find yourself sometimes on staff when things don't have to be said. You sort of know."

Democrats swarm

Christie is now campaigning for fellow GOP governors as chairman of the Republican Governors Association and is seen as a prime political target for national Democrats.

They rarely attacked him during his re-election campaign but are now becoming more aggressive with the bridge controversy unfolding.

"These revelations are troubling for any public official, but they also indicate what we've come to expect from Governor

Christie -- when people oppose him, he exacts retribution. When people question him, he belittles and snidely jokes. And when anyone dares to look into his administration, he bullies and attacks," U.S. Rep. Debbie Wasserman Schultz of Florida, the Democratic National Committee chairwoman, said in a prepared statement.

A source close to Christie said "there will probably be some sacrificial firing, and that'll be it."